The Framingham Offspring Study has been undertaken in order to explore the relation between alcohol and breast cancer. This cohort study consists of 5,135 children (2,646 female, 2,489 male) of the members of the original Framingham Heart Study Cohort. The baseline examination period was 1972-77 (Cycle 1). Subsequent follow-up periods were 1979-82 (Cycle 2) and 1984-5 (Cycle 3), with Cycle 4 currently ongoing. Alcohol consumption, both frequency and amount by type of beverage, has been ascertained at each cycle. Information on socioeconomic status, and reproductive and family history has been routinely collected. These additional data are important in controlling for variables that might confound an observed association between alcohol and breast cancer. Six hundred cancers (300 in both men and women) are projected (based on the application of SEER rates to the cohort). This includes approximately 100 breast cancer cases in women, 110 lung cancers (80 in men), and 110 colorectal cancers (60 in men). A similar study (ZO1 CN 00146-02 CPSB) is being conducted on the original cohort.